In German Patent 41 09 481 a snap ring of a special shape is under compression in a deep groove of a shaft during insertion of the shaft into a hub and springs out into a groove of the hub upon reaching an end position. When the hub and shaft are provided with splines as in this system, the snap ring is located within the axial extent of the splines so that it frequently is not visible nor accessible for disassembly at least from one side of the system. The visual inspection of the snap ring is impeded and the mode by which the hub is held on the shaft by the snap ring, i.e. in form retention, force retention or both is limited. The splines may be weakened by the formation of the grooves therein and, since grooving often must occur through the spline, for the formation of burrs and sharp edges is possible.
In German patent 42 07 839, similar problems are encountered because the special contours for retaining the snap ring are provided within the axial extent of the splines. During insertion of the shaft in the hub, the snap ring is displaced from one groove of the shaft to another and at the same time into a groove of the hub. This construction tends to weaken the spline and to be somewhat complex to produce. It also creates problems in assembly and disassembly.